This invention relates to a disc player having a centering mechanism which, in inserting a disc into the disc inserting opening thereof, operates to position the disc at the center of the disc inserting opening.
Recently, a compact disc has been developed which has a recording layer having pits corresponding to digital signals obtained by converting analog sounds (hereinafter referred to as "a disc"). With the disc, analog sounds are optically reproduced by using a laser beam applied by the reading head of a CD (compact disc) player. The disc is much superior both in tone quality and in operability to conventional LP record discs. Hence, the compact disc together with its CD player has quickly come into wide use. Accordingly, CD players to be mounted on vehicles have been developed. One example of the vehicle disc player is as shown in FIG. 1. In FIG. 1, reference numeral 101 designates a disc of 12 cm in diameter in which pieces of music have been recorded. When the disc 101 is inserted into a disc inserting opening 102, it is conveyed to a predetermined position (which is substantially the center of the CD player) by a loading mechanism 103, where it is fixedly mounted on the turntable 105 by a clamper arm 104. The disc 101 thus mounted is rotated by a spindle motor (not shown), so that the pieces of music are reproduced with a reading head (not shown). In the reading head are supported in floating manner so that they are substantially free from vibration during traveling.
On the other hand, a disc 106 of 8 cm in diameter, which is much smaller in diameter than the disc 101 of 12 cm in diameter, has been proposed in the art.
However, such a prior art CD player is constructed such that when a small-diameter disc 106 is to be inserted into the disc inserting opening, care must be taken to guide the disc so that the center of the disc is aligned with the center of the disc inserting opening. If the disc 106 inserted through the disc inserting opening 102 is not reasonably aligned with its supposed insertion path, the disc is not transferred to a predetermined position. Since the automotive CD player is subjected to vibration while the vehicle is running, extreme care must be taken when the small-diameter disc is to be inserted into the middle of the disc inserting opening 102.
Thus, one possible solution to this problem is to provide near the disc inserting opening 102 a centering mechanism that allows the disc 106 to be positioned in the middle of the disc inserting opening 102. This centering mechanism permits the disc 106 to be transferred passing through the center of the disc inserting opening to the turntable and then clamps the disc onto the turntable by means of the clamp arm.
When the CD player is tilted for some reason while the vehicle is running, the disc inserting opening 102 is also inclined causing the center of the disc to be misaligned with the center of the turntable since the turntable is supported in a floating condition with shock absorbing effect. In which case, guiding the disc at the center position of the disc inserting opening 102 by holding the disc for a long time may cause the disc to become rather misaligned with the clamp position on the turntable where the disc is supposed to clamped, disturbing the operation of the centering mechanism provided on float-supporting mechanism.
The present invention contemplates the above drawbacks, and is to provide a disc reproducing apparatus, in which the centering mechanism permits the disc to be easily inserted into the center position of the disc inserting opening even when the vehicle CD player undergoes vibration while the vehicle is running, and the centering mechanism provided at the disc inserting opening does not disturb the operation of the centering mechanism provided in the floating supporting mechanism.
On the other hand, with the prior art CD player, the clamp position is a position where the inserted disc 101 having a diameter of 12 centimeters is transferred till it abuts the stopper to be blocked. The small-diameter disc 106 inserted through the disc inserting opening of eight centimeters is transferred till it abuts the stopper, then the disc will be transferred too far beyond the clamp position, resulting in difficulty in clamping the disc. The present invention also contemplates the above mentioned drawback and an object of the invention is to provide a disc reproducing apparatus in which the small-diameter disc inserted into the disc inserting opening can be accurately positioned at the clamp position on the turntable.